What is an antitrust law? Where is it found? What is the historical background of the antitrust laws? How have antitrust laws changed over the years? What are some current issues and/or cases that are affected by antitrust law?

What is an antitrust law? Where is it found? What is the historical background of the antitrust laws? How have antitrust laws changed over the years? What are some current issues and/or cases that are affected by antitrust law?